Hydrangea plant named &#39;hortmablo&#39;

ABSTRACT

A new and distinct cultivar of  Hydrangea  plant named ‘Hortmablo’, characterized by its upright to broadly spreading plant habit; moderately vigorous to vigorous growth habit and moderate to rapid growth rate; freely branching habit with strong and thick sturdy stems; relatively large leaves; mophead-type inflorescences with large light pink-colored sterile flowers; and good postproduction longevity.

Botanical designation: Hydrangea macrophylla.

Cultivar denomination: ‘HORTMABLO’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of Hydrangea plant, botanically known as Hydrangea macrophylla, commercially referred to as a mophead-type Hydrangea and hereinafter referred to by the name ‘Hortmablo’.

The new Hydrangea plant is a product of a planned breeding program conducted by the Inventor in Boskoop, The Netherlands. The objective of the breeding program was to create new Hydrangea plants with large inflorescences with numerous and attractive sterile flowers and good postproduction longevity.

The new Hydrangea plant originated from a cross-pollination made by the Inventor on Jun. 2, 2010 in Boskoop, The Netherlands, of a proprietary selection of Hydrangea macrophylla identified as code number 08-038-06, not patented, as the female, or seed, parent with Hydrangea macrophylla ‘Snowball’, not patented, as the male, or pollen, parent. The new Hydrangea plant was discovered and selected by the Inventor as a single flowering plant from within the progeny of the stated cross-pollination in a controlled greenhouse environment in Boskoop, The Netherlands in July, 2014.

Asexual reproduction of the new Hydrangea plant by vegetative terminal cuttings in a controlled environment in Boskoop, The Netherlands has shown that the unique features of this new Hydrangea plant are stable and reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

Plants of the new Hydrangea have not been observed under all possible combinations of environmental conditions and cultural practices. The phenotype may vary somewhat with variations in environmental conditions such as temperature and light intensity without, however, any variance in genotype.

The following traits have been repeatedly observed and are determined to be the unique characteristics of ‘Hortmablo’. These characteristics in combination distinguish ‘Hortmablo’ as a new and distinct Hydrangea plant:

-   -   1. Upright to broadly spreading plant habit.     -   2. Moderately vigorous to vigorous growth habit and moderate to         rapid growth rate.     -   3. Freely branching habit with strong and thick sturdy stems.     -   4. Relatively large leaves.     -   5. Mophead-type inflorescences with large light pink-colored         sterile flowers.     -   6. Good postproduction longevity.

Plants of the new Hydrangea can be compared to plants of the female parent selection. Plants of the new Hydrangea differ primarily from plants of the female parent selection in sterile flower color as sterile flower sepals of plants of the female parent selection are darker in color than sterile flower sepals of plants of the new Hydrangea. In addition, plants of the new Hydrangea have larger leaves and sterile flower sepals than plants of the female parent selection.

Plants of the new Hydrangea can be compared to plants of the male parent, ‘Snowball’. Plants of the new Hydrangea differ primarily from plants of ‘Snowball’ in sterile flower color as plants of ‘Snowball’ have white-colored sterile flower sepals. In addition, inflorescences of plants of the new Hydrangea are more flattened than and not as globular as inflorescences of plants of ‘Snowball’.

Plants of the new Hydrangea can be compared to plants of the Hydrangea macrophylla ‘Hokomathyst’, disclosed in U.S. Plant Pat. No. 22,261. In side-by-side comparisons plants of the new Hydrangea differ primarily from plants of ‘Hokomathyst’ in the following characteristics:

-   -   1. Plants of the new Hydrangea have larger leaves than plants of         ‘Hokomathyst’.     -   2. Plants of the new Hydrangea have larger sterile flower sepals         than plants of ‘Hokomathyst’.     -   3. Plants of the new Hydrangea and ‘Hokomathyst’ differ in         sterile flower color as plants of ‘Hokomathyst’ have red         purple-colored sterile flower sepals with green-colored margins.

Plants of the new Hydrangea can also be compared to plants of the Hydrangea macrophylla ‘Hortmasnodo’, not patented. In side-by-side comparisons plants of the new Hydrangea differ primarily from plants of ‘Hortmasnodo’ in sterile flower color as plants of ‘Hortmasnodo’ have sterile flower sepals that are white in color.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying colored photographs illustrate the unique appearance of the new Hydrangea plant showing the colors as true as it is reasonably possible to obtain in colored reproductions of this type. Colors in the photographs may differ from the color values cited in the detailed botanical description which accurately describe the colors of the new Hydrangea plant.

The photograph on the first sheet is a side perspective view of a typical flowering plant of ‘Hortmablo’.

The photograph on the second sheet is a close-up view of a typical inflorescence of ‘Hortmablo’.

DETAILED BOTANICAL DESCRIPTION

Plants used in the aforementioned photographs and in the following description were grown during the late spring in 17-cm containers in a glass-covered greenhouse in Boskoop, The Netherlands and under cultural practices typical of commercial Hydrangea production. During the production of the plants, day temperatures ranged from 18° C. to 25° C. and night temperatures ranged from 16° C. to 17° C. Plants of the new Hydrangea were two years old when the photographs and description were taken. Plants of the new Hydrangea are not typically treated with aluminum sulfate to “blue” the inflorescences. In the following description, color references are made to The Royal Horticultural Society Colour Chart, 2015 Edition, except where general terms of ordinary dictionary significance are used.

BOTANICAL DESCRIPTION Hydrangea macrophylla ‘Hortmablo’. PARENTAGE

-   Female, or seed, parent: Proprietary selection of Hydrangea     macrophylla identified as code number 08-038-06, not patented. -   Male, or pollen, parent: Hydrangea macrophylla ‘Snowball’, not     patented.

PROPAGATION

-   Type cutting: By vegetative terminal cuttings. -   Time to initiate roots, summer: About three weeks at temperatures     about 15° C. to 25° C. -   Time to produce a rooted young plant, summer: About six weeks at     temperatures about 15° C. to 25° C. -   Root description: Medium in thickness, fibrous; typically creamy     white in color, actual color of the roots is dependent on substrate     composition, water quality, fertilizer type and formulation,     substrate temperature and physiological age of roots. -   Rooting habit: Moderately freely branching; medium density.

PLANT DESCRIPTION

-   Plant and growth habit: Upright and broadly spreading plant habit;     overall plant shape is flattened globular; strong and sturdy lateral     branches; moderate to rapid growth rate and moderately vigorous to     vigorous growth habit. -   Plant height: About 55 cm. -   Plant diameter or area of spread: About 68.5 cm.

LATERAL BRANCH DESCRIPTION

-   Branching habit: Freely branching habit; when pinched, about ten     lateral branches develop per plant. -   Length: About 30.9 cm. -   Diameter: About 8 mm. -   Internode length: About 9.2 cm. -   Texture: Smooth, glabrous; fully developed, woody. -   Aspect: Upright to about 30° from vertical. -   Strength: Strong, sturdy. -   Color:     -   -   When developing.—Close to 144B.         -   Developed.—Close to 144A to 144B; at the internodes, tinged             with close to N186C; when woody, close to 199C and 200D. -   Lenticels:     -   -   Density.—Moderate to dense.         -   Length.—About 2.5 mm.         -   Diameter.—About 0.5 mm.         -   Color.—Close to N186C.

LEAF DESCRIPTION

-   Arrangement: Opposite, simple. -   Length: About 15.3 cm. -   Width: About 10.4 cm. -   Shape: Broadly elliptic to broadly ovate. -   Apex: Apiculate. -   Base: Short attenuate. -   Margin: Serrate. -   Texture, upper surface: Smooth to slightly rugose, glabrous. -   Texture, lower surface: Smooth to slightly rugose, surface mostly     glabrous, however small tufts of short hairs present at vein axils. -   Venation pattern: Pinnate. -   Color:     -   -   Developing leaves, upper surface.—Close to 144A.         -   Developing leaves, lower surface.—Close to 144B.         -   Fully expanded leaves, upper surface.—Close to 137A;             venation, close to 145A to 145B.         -   Fully expanded leaves, lower surface.—Close to 144A;             venation, close to 145B. -   Petioles:     -   -   Length.—About 2.8 cm.         -   Diameter.—About 5 mm.         -   Texture and luster, upper and lower surfaces.—Smooth,             glabrous; slightly glossy.         -   Color, upper surface.—Close to 145B; towards the margins,             close to 144B.         -   Color, lower surface.—Close to 145A.

FLOWER DESCRIPTION

-   Flower type and habit: Showy sterile flowers and small inconspicuous     fertile flowers arranged on mophead-type terminal panicles; panicles     globular and slightly flattened in shape; fertile flowers face     mostly upright and sterile flowers face upright to outwardly and     slightly drooping depending on their position in the inflorescence. -   Fragrance: None detected. -   Natural flowering season: Plants flower from late spring to late     summer in The Netherlands. -   Flower longevity: Fertile flowers last about five days on the plant,     fertile flowers not persistent; sterile flowers last about six weeks     on the plant, sterile flowers persistent. -   Quantity of flowers: Freely flowering habit; about 20 fertile     flowers per panicle and about 120 sterile flowers per panicle. -   Panicle height: About 11.5 cm. -   Panicle diameter: About 17.9 cm. -   Fertile flower buds:     -   -   Length.—About 4 mm.         -   Diameter.—About 4 mm.         -   Shape.—Obovate.         -   Color.—Close to NN155B; towards the base, close to 145B to             145C. -   Sterile flower buds:     -   -   Length.—About 3 mm.         -   Diameter.—About 3.5 mm.         -   Shape.—Flattened globular.         -   Color.—Close to 69B to 69C. -   Fertile flower diameter: About 1.2 cm. -   Fertile flower depth (height): About 9 mm. -   Sterile flower diameter: About 5.5 cm. -   Sterile flower depth (height): About 2.4 cm. -   Petals, fertile flowers:     -   -   Quantity and arrangement.—Four or occasionally five in a             single whorl.         -   Length.—About 6 mm.         -   Width.—About 3 mm.         -   Shape.—Ovate, concave.         -   Apex.—Acute.         -   Base.—Cuneate.         -   Margin.—Entire.         -   Texture and luster, upper and lower surfaces.—Smooth,             glabrous; matte.         -   Color.—When opening and fully opened, upper surface: Close             to 155C. When opening and fully opened, lower surface: Close             to 155C; towards the base, close to NN155D. -   Petals, sterile flowers:     -   -   Quantity and arrangement.—About four or occasionally five in             a single whorl.         -   Length.—About 4 mm.         -   Width.—About 3 mm.         -   Shape.—Ovate, concave.         -   Apex.—Acute.         -   Base.—Cuneate.         -   Margin.—Entire.         -   Texture and luster, upper and lower surfaces.—Smooth,             glabrous; matte.         -   Color.—When opening, upper surface: Close to 75D; towards             the margins, close to NN155D. When opening, lower surface:             Close to NN155A; towards the apex, tinged with close to 75D.             Fully opened, upper surface: Close to NN155A; slightly             tinged with close to 75D. Fully opened, lower surface: Close             to NN155A; towards the apex, slightly tinged with close to             75D. -   Sepals, fertile flowers:     -   -   Quantity and arrangement.—Five or occasionally six in a             single whorl.         -   Length.—About 2 mm.         -   Width.—About 1.5 mm.         -   Shape.—Ovate.         -   Apex.—Acute.         -   Base.—Broadly cuneate.         -   Margin.—Entire.         -   Texture and luster, upper and lower surfaces.—Smooth,             glabrous; matte.         -   Color.—When opening, upper and lower surfaces: Close to             between 150D and 155A. Fully opened, upper and lower             surfaces: Close to between 150D and 155A; color does not             change with development. -   Sepals, sterile flowers:     -   -   Quantity and arrangement.—Four in a single whorl.         -   Length.—About 2.8 cm.         -   Width.—About 3.9 cm.         -   Shape.—Roughly reniform.         -   Apex.—Emarginate, praemorse.         -   Base.—Cuneate.         -   Margin.—Crenate.         -   Texture and luster, upper and lower surfaces.—Smooth,             glabrous; matte.         -   Color.—When opening, upper and lower surfaces: Close to             NN155D; distally, tinged with close to 69D. Fully opened,             upper surface: Close to 69B; towards the base, close to 65B             to 65C; color becoming closer to 145B with development.             Fully opened, lower surface: Close to 69B; venation, close             to 65B; color becoming closer to 145C with development. -   Pedicels, fertile flowers:     -   -   Length.—About 2 mm.         -   Diameter.—About 1 mm.         -   Strength.—Moderately strong.         -   Aspect.—About 20° from vertical.         -   Texture and luster.—Moderately to densely pubescent; matte.         -   Color.—Close to 65D. -   Pedicels, sterile flowers:     -   -   Length.—About 2.2 cm.         -   Diameter.—About 2 mm.         -   Strength.—Moderately strong.         -   Aspect.—About 45° from vertical.         -   Texture and luster.—Moderately pubescent; matte.         -   Color.—Close to N155B. -   Reproductive organs, fertile flowers:     -   -   Stamens.—Quantity per flower: About ten. Filament length:             About 5.5 mm. Filament color: Close to NN155D. Anther             length: About 1 mm. Anther shape: Oblong. Anther color:             Close to 157D. Pollen amount: Moderate. Pollen color: Close             to 159D.         -   Pistils.—Pistil quantity per flower: About three or four.             Pistil length: About 1 mm. Stigma shape: Club-shaped. Stigma             color: Close to NN155D. Style length: About 0.5 mm. Style             color: Close to NN155B. Ovary color: Close to between 150D             and 155A. -   Reproductive organs, sterile flowers:     -   -   Stamens.—Quantity per flower: About eight. Filament length:             About 2.5 mm. Filament color: Close to NN155C. Anther             length: About 1 mm. Anther shape: Oblong. Anther color:             Close to 155A. Pollen amount: Moderate. Pollen color: Close             to 159D.         -   Pistils.—Pistil quantity per flower: About three or four.             Pistil length: About 1 mm. Stigma shape: Club-shaped. Stigma             color: Close to NN155A. Style length: About 1 mm. Style             color: Close to NN155A. Ovary color: Close to 145D. -   Seeds: Seed development has not been observed on plants of the new     Hydrangea to date.

DISEASE & PEST RESISTANCE Under commercial production conditions, plants of the new Hydrangea have not been observed to be resistant to pathogens and pests common to Hydrangea plants. TEMPERATURE TOLERANCE Plants of the new Hydrangea have been shown to be suitable for USDA Hardiness Zones 5 to 9. 

It is claimed:
 1. A new and distinct Hydrangea plant named ‘Hortmablo’ as illustrated and described. 